In known hybrid or fully electrically driven vehicles, an acceleration command of a driver is typically implemented by evaluating a signal describing the actuation of an accelerator pedal of the motor vehicle by way of a control device assigned to an electric machine. Depending on said signal, the electric machine is then controlled to generate a determined rotational speed or a determined torque. For improvement of the energy consumption of the electric machine, it is additionally known, when the motor vehicle is at a standstill or when the motor vehicle is in non-actively driven coasting operation, to withdraw a magnetic field in the electric machine and to build it up again only when there is a renewed acceleration command. In this way, in an asynchronous machine with squirrel cage rotors, the rotating field generated by stator windings of the electric machine is reduced or completely cancelled at the standstill or in coasting operation, for example. However, the renewed buildup of the rotating field during a desired acceleration of the motor vehicle demands a certain latency time, during which the increase in rotational speed cannot yet be implemented. This reduces the effective acceleration capability of the motor vehicle and lengthens, for example, the time span for an acceleration from 0 km/h to 100 km/h.
For improvement of the acceleration capability of electrically driven motor vehicles, it is known from US 2010/0 116 575 A1 to provide a step-up converter, which supplies an increased voltage to an inverter supplying the stator windings. Additionally provided is a control device that limits the increased voltage when a blocked state of the supplied electric machine is detected and both an accelerator pedal and a brake pedal are not being actuated. However, a reduction in the previously mentioned latency times cannot be implemented in this way.